-89.22% is the change from 640 to 69
Calculation steps:
[( 69 - 640 ) ÷ 640] x 100 = -89.22%
Formula
Percentage change = [(69 - 640) / 640] x 100
Subtract the new number by the original number
69 - 640 = -571
-571 ÷ 640 = -0.8921875
-0.8921875 x 100 = -89.22%